REDUCING SLUDGE VOLUME IN PIT LATRINES: CAN LATRINE ADDITIVES IN GHANA HELP?

Public latrines are patronized by more than 34% of the Ghanaian population. With high usage rate, the pits get full quickly requiring frequent desludging. One of the solutions for dealing with full pits is the use of pit latrine additives but studies have produced variable results. This research assessed excreta degradability and efficacy of pit latrine additives in Cape Coast. Homogenous fresh faeces were taken from three public pit latrines for characterization and additives study. The efficacy of two commercial additives and household ash were tested at the laboratory for 30days at ambient temperature (22°C) under aerobic conditions. For each trial, three different treatments (control, water and additives) were studied. The results show that the soluble COD, particulate COD, moisture content and organic solids content were respectively 0.04 – 0.08 mg/mg dry sample, 0.10 – 0.24 mg/mg dry sample, 70 – 76% dry sample and 71 – 76% dry sample for all the three pits before additives application. All the samples recorded a reduction in the characteristics after additives application except for Additive B which recorded an increase. The mass of waste in each unit decreased with time over the 30days after applying the additives. Except for additive B (2.6% and 4.1%), all the other treatments recorded a net mass loss of 5.6% - 7.7% of their original mass. However, additives A and C did not have any significant effect on the physico-chemical characteristics and degradation rate of the fresh faeces.